diff options
Diffstat (limited to 'drivers/hwmon/pwm-fan.c')
| -rw-r--r-- | drivers/hwmon/pwm-fan.c | 116 |
1 files changed, 108 insertions, 8 deletions
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 167221c7628a..eead8afe6447 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -18,6 +18,7 @@ #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> +#include <linux/interrupt.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of.h> @@ -26,6 +27,7 @@ #include <linux/regulator/consumer.h> #include <linux/sysfs.h> #include <linux/thermal.h> +#include <linux/timer.h> #define MAX_PWM 255 @@ -33,6 +35,14 @@ struct pwm_fan_ctx { struct mutex lock; struct pwm_device *pwm; struct regulator *reg_en; + + int irq; + atomic_t pulses; + unsigned int rpm; + u8 pulses_per_revolution; + ktime_t sample_start; + struct timer_list rpm_timer; + unsigned int pwm_value; unsigned int pwm_fan_state; unsigned int pwm_fan_max_state; @@ -40,6 +50,32 @@ struct pwm_fan_ctx { struct thermal_cooling_device *cdev; }; +/* This handler assumes self resetting edge triggered interrupt. */ +static irqreturn_t pulse_handler(int irq, void *dev_id) +{ + struct pwm_fan_ctx *ctx = dev_id; + + atomic_inc(&ctx->pulses); + + return IRQ_HANDLED; +} + +static void sample_timer(struct timer_list *t) +{ + struct pwm_fan_ctx *ctx = from_timer(ctx, t, rpm_timer); + int pulses; + u64 tmp; + + pulses = atomic_read(&ctx->pulses); + atomic_sub(pulses, &ctx->pulses); + tmp = (u64)pulses * ktime_ms_delta(ktime_get(), ctx->sample_start) * 60; + do_div(tmp, ctx->pulses_per_revolution * 1000); + ctx->rpm = tmp; + + ctx->sample_start = ktime_get(); + mod_timer(&ctx->rpm_timer, jiffies + HZ); +} + static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { unsigned long period; @@ -100,15 +136,45 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *attr, return sprintf(buf, "%u\n", ctx->pwm_value); } +static ssize_t rpm_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", ctx->rpm); +} static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); +static SENSOR_DEVICE_ATTR_RO(fan1_input, rpm, 0); static struct attribute *pwm_fan_attrs[] = { &sensor_dev_attr_pwm1.dev_attr.attr, + &sensor_dev_attr_fan1_input.dev_attr.attr, NULL, }; -ATTRIBUTE_GROUPS(pwm_fan); +static umode_t pwm_fan_attrs_visible(struct kobject *kobj, struct attribute *a, + int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + + /* Hide fan_input in case no interrupt is available */ + if (n == 1 && ctx->irq <= 0) + return 0; + + return a->mode; +} + +static const struct attribute_group pwm_fan_group = { + .attrs = pwm_fan_attrs, + .is_visible = pwm_fan_attrs_visible, +}; + +static const struct attribute_group *pwm_fan_groups[] = { + &pwm_fan_group, + NULL, +}; /* thermal cooling device callbacks */ static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev, @@ -214,6 +280,7 @@ static int pwm_fan_probe(struct platform_device *pdev) struct device *hwmon; int ret; struct pwm_state state = { }; + u32 ppr = 2; ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); if (!ctx) @@ -233,6 +300,10 @@ static int pwm_fan_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ctx); + ctx->irq = platform_get_irq(pdev, 0); + if (ctx->irq == -EPROBE_DEFER) + return ctx->irq; + ctx->reg_en = devm_regulator_get_optional(&pdev->dev, "fan"); if (IS_ERR(ctx->reg_en)) { if (PTR_ERR(ctx->reg_en) != -ENODEV) @@ -257,21 +328,44 @@ static int pwm_fan_probe(struct platform_device *pdev) ret = pwm_apply_state(ctx->pwm, &state); if (ret) { - dev_err(&pdev->dev, "Failed to configure PWM\n"); + dev_err(&pdev->dev, "Failed to configure PWM: %d\n", ret); goto err_reg_disable; } + timer_setup(&ctx->rpm_timer, sample_timer, 0); + + of_property_read_u32(pdev->dev.of_node, "pulses-per-revolution", &ppr); + ctx->pulses_per_revolution = ppr; + if (!ctx->pulses_per_revolution) { + dev_err(&pdev->dev, "pulses-per-revolution can't be zero.\n"); + ret = -EINVAL; + goto err_pwm_disable; + } + + if (ctx->irq > 0) { + ret = devm_request_irq(&pdev->dev, ctx->irq, pulse_handler, 0, + pdev->name, ctx); + if (ret) { + dev_err(&pdev->dev, + "Failed to request interrupt: %d\n", ret); + goto err_pwm_disable; + } + ctx->sample_start = ktime_get(); + mod_timer(&ctx->rpm_timer, jiffies + HZ); + } + hwmon = devm_hwmon_device_register_with_groups(&pdev->dev, "pwmfan", ctx, pwm_fan_groups); if (IS_ERR(hwmon)) { - dev_err(&pdev->dev, "Failed to register hwmon device\n"); ret = PTR_ERR(hwmon); - goto err_pwm_disable; + dev_err(&pdev->dev, + "Failed to register hwmon device: %d\n", ret); + goto err_del_timer; } ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); if (ret) - return ret; + goto err_del_timer; ctx->pwm_fan_state = ctx->pwm_fan_max_state; if (IS_ENABLED(CONFIG_THERMAL)) { @@ -279,10 +373,11 @@ static int pwm_fan_probe(struct platform_device *pdev) "pwm-fan", ctx, &pwm_fan_cooling_ops); if (IS_ERR(cdev)) { - dev_err(&pdev->dev, - "Failed to register pwm-fan as cooling device"); ret = PTR_ERR(cdev); - goto err_pwm_disable; + dev_err(&pdev->dev, + "Failed to register pwm-fan as cooling device: %d\n", + ret); + goto err_del_timer; } ctx->cdev = cdev; thermal_cdev_update(cdev); @@ -290,6 +385,9 @@ static int pwm_fan_probe(struct platform_device *pdev) return 0; +err_del_timer: + del_timer_sync(&ctx->rpm_timer); + err_pwm_disable: state.enabled = false; pwm_apply_state(ctx->pwm, &state); @@ -306,6 +404,8 @@ static int pwm_fan_remove(struct platform_device *pdev) struct pwm_fan_ctx *ctx = platform_get_drvdata(pdev); thermal_cooling_device_unregister(ctx->cdev); + del_timer_sync(&ctx->rpm_timer); + if (ctx->pwm_value) pwm_disable(ctx->pwm); |